Effects of irrigation water quality and soil type on the soil and plant associated microbiome, abundance, diversity and transferability of antibiotic resistance genes in Gram-negative bacteria

灌溉水质和土壤类型对土壤和植物相关微生物组、革兰氏阴性菌抗生素抗性基因丰度、多样性和可转移性的影响

• 批准号: 462480705
• 负责人: Professorin Dr. Kornelia Smalla
• 金额: --
• 依托单位: Institut für Epidemiologie und Pathogendiagnostik
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/462480705?language=en
• 关键词: Effects; irrigation; water; quality; soil

The reuse of wastewater for irrigation in agriculture is an efficient way of saving water and increasing food production for a growing population under conditions of climate change. Investments in infrastructure cause a shift from irrigation with untreated wastewater to irrigation with treated wastewater in many countries. SP 5 of the proposed research unit will contribute to testing the hypotheses that i) environmental concentrations of pollutants released from soil and taken up by plants are high enough to select antibiotic resistance and trigger horizontal gene transfer in soils and plants and ii) the soil type modulates the release of pollutants and the associated selection of antibiotic resistance.The effect of the addition of treated or untreated wastewater to Leptosols, Phaeozems and Vertisols, that have been irrigated with untreated wastewater for >80 years, on the microbial community composition and the abundance of antibiotic resistance genes (ARGs) as well as mobile genetic elements (MGEs) associated with Gram-negative bacteria will be tested in a joint incubation and batch experiment based on total community DNA. For a subset of soil samples horizontal gene transfer (HGT) rates among Gram-negative bacteria will be determined. Isolated Enterobacteria (SP 6) will be screened for the presence of transferable plasmids. The mobilization of ARGs to InCP-1 plasmids due to selection by antibiotics and disinfectants added with wastewater and released from soil will be tested in a satellite experiment, in which the soil bacterium Acinetobacter baylyi BD413 carrying IncP-1 plasmids without antibiotic resistance genes will be applied to the differently treated soils, re-isolated after 28 days and screened for acquired ARGs by IncP-1 plasmids.The relevance of plants for the selection and spreading of ARGs and the transfer into the food chain will be investigated in the joint soil column experiment with monolithic “undisturbed” soil columns planted with cilantro (Coriandrum sativum). SP 5 will assess the microbial community composition in phyllosphere and roots/rhizosphere, the relative abundance of ARGs and MGEs of Gram-negative bacteria, and HGT-rates among Gram-negative bacteria.SP 5 contributes the same expertise and techniques to the joint field experiment with Phaeozem soil irrigated with untreated wastewater for >80 years and planted with cilantro in order to bridge controlled laboratory and greenhouse experiments to real world conditions, especially regarding the effects of irrigation water quality on phyllosphere bacteria, which are difficult to study under greenhouse conditions (reduced radiation and dust inputs).By linking its results and expertise to the data and knowledge of the other SPs of the RU also by means of the integrated mathematical model (SP 7), SP 5 contributes to a mechanistic understanding of interactions between pollutants, antibiotic resistance and pathogens in changing wastewater irrigation systems.

在气候变化的条件下，将废水再用于农业灌溉是节约用水和为不断增长的人口增加粮食产量的有效途径。在许多国家，对基础设施的投资导致从用未经处理的废水灌溉转向用经处理的废水灌溉。拟议研究单位的SP 5将有助于测试以下假设：i）从土壤释放并被植物吸收的污染物的环境浓度足够高，以选择抗生素抗性并引发土壤和植物的水平基因转移; ii）土壤类型调节污染物的释放和抗生素抗性的相关选择。将在基于总群落DNA的联合培养和分批实验中测试用未经处理的废水灌溉超过80年的薄土、黑土和变性土对微生物群落组成和抗生素抗性基因（ARG）丰度以及与革兰氏阴性菌相关的移动的遗传元件（MGE）的影响。对于土壤样品的一个子集，将确定革兰氏阴性菌之间的水平基因转移（HGT）率。将筛选分离的肠杆菌（SP 6）是否存在可转移质粒。将在卫星实验中测试ARG向InCP-1质粒的移动，这是由于添加有废水并从土壤中释放的抗生素和消毒剂的选择，其中将携带无抗生素抗性基因的IncP-1质粒的土壤细菌Baylyi BD 413应用于不同处理的土壤，28天后重新分离，并通过IncP-1质粒筛选获得的ARGs。将在整体“未扰动”的联合土柱实验中研究植物对ARGs选择和传播以及转移到食物链中的相关性。种植香菜的土柱。SP 5将评估叶际和根/根际的微生物群落组成，革兰氏阴性菌的ARG和MGE的相对丰度，和HGT率之间的革兰氏阴性菌。SP 5贡献了相同的专业知识和技术的联合实地实验与黑土土壤灌溉未经处理的废水> 80年，种植香菜，以桥梁控制实验室和温室实验，以真实的世界条件，特别是关于灌溉水质对叶际细菌的影响，在温室条件下很难研究（减少辐射和尘埃输入）。通过将其结果和专业知识与RU其他SP的数据和知识联系起来，也通过综合数学模型（SP 7），SP 5有助于从机理上理解污染物之间的相互作用，改变废水灌溉系统中的抗生素耐药性和病原体。